The present invention is directed towards silanes and disiloxanes with the bulky, (p-t-butylphenyl)ethyl substituent. The compounds of the present invention are useful as protecting groups in the synthesis of biological macromolecules.
Silylation with bulky groups is important in the production of many biological macromolecules. Bulky silane groups are used to protect certain functional groups during intermediate steps in the synthesis of these molecules and to sterically control other synthetic steps. For example, the t-butyldimethylsilyl protecting group was used in prostaglandin synthesis by Corey and Venkateswarlu, J.Am.Chem. Soc. 94: 6190, (1962). The t-butyldiphenylsilyl group was used by Brown et al in the synthesis of transfer riboneucleic acid in "Chemical Synthesis And Cloning Of Tyrosine t-RNA Gene", Meth. In Enzymology, 68:109 (1978).
The use of bulky silyl groups, in contrast to older methods in which simple trimethylsilyl groups are used, is related to the increased ability of such compounds to sterically control intermediate synthetic steps and the increased resistance of such groups to hydrolysis. Presently, t-butylsilyl protecting groups are used for this purpose.
Currently, processes for introducing t-butyl groups are generally expensive and awkward. These processes involve the reaction of t-butyl lithium with a chlorosilane in the following manner: EQU (CH.sub.3).sub.3 CLi+(CH.sub.3).sub.2 SiCl.sub.2 .fwdarw.(CH.sub.3).sub.3 C(CH.sub.3).sub.2 SiCl+LiCl
It is the object of this invention to provide bulky silane groups, having increased ability to sterically control synthetic steps and increased stability. It is a further object of this invention to provide an easier and less expensive method of producing such compounds.